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Journal Cover Animal Behaviour
  [SJR: 1.907]   [H-I: 126]   [172 followers]  Follow
    
   Hybrid Journal Hybrid journal (It can contain Open Access articles)
   ISSN (Print) 0003-3472 - ISSN (Online) 1095-8282
   Published by Elsevier Homepage  [3089 journals]
  • Are all motivation tests the same' The effect of two adaptations to a
           three-chamber consumer demand study in ferrets
    • Authors: Marsinah L. Reijgwart; Claudia M. Vinke; Coenraad F.M. Hendriksen; Miriam van der Meer; Nico J. Schoemaker; Yvonne R.A. van Zeeland
      Pages: 1 - 11
      Abstract: Publication date: January 2018
      Source:Animal Behaviour, Volume 135
      Author(s): Marsinah L. Reijgwart, Claudia M. Vinke, Coenraad F.M. Hendriksen, Miriam van der Meer, Nico J. Schoemaker, Yvonne R.A. van Zeeland
      Ferrets, Mustela putorius furo, are increasingly used in infectious disease studies, particularly in influenza research. Which specific housing conditions and environmental enrichments are of particular importance for ferrets have not been part of a systematic evaluation. The motivation ferrets showed to reach different enrichments was assessed in multiple consumer demand study set-ups. To address the question whether these consumer demand set-ups give similar results, we assessed the effects of two ways of offering enrichments concurrently instead of consecutively. Six ovariectomized female ferrets were successively tested in a seven-chamber (7Ch), three-chamber (3Ch) and three-chamber ‘all-but-one’ (ABO) set-up. We compared the maximum price paid, visit number, visit duration and interaction time with the enrichments in the 3Ch versus the 7Ch and ABO set-ups, respectively. Compared to the 3Ch set-up, the ferrets in the ABO and 7Ch set-up showed a lower motivation to access, paid fewer and shorter visits to and interacted less with the enrichments. In the 7Ch, the ferrets especially showed a lower motivation for the less preferred enrichments and the empty chamber. These findings indicate that testing all the enrichments concurrently in the 7Ch set-up forced the ferrets to make more economic decisions, thereby providing more valuable information on how different enrichments are valued relative to one other. Adding preferred enrichment items to the home chamber, as was done in the ABO set-up, might have reduced the motivation to access or look for additional enrichment items. However, this set-up might not have a closed economy, making the ABO set-up unsuitable. Based on these findings, we advise testing all the enrichment categories concurrently instead of consecutively and keeping the number of items in the home cage to a minimum when performing a consumer demand study, as this appears the most optimal set-up to determine motivational priorities for resources in ferrets.

      PubDate: 2017-12-12T02:10:15Z
      DOI: 10.1016/j.anbehav.2017.10.026
      Issue No: Vol. 135 (2017)
       
  • Social networks of spotted hyaenas in areas of contrasting human activity
           and infrastructure
    • Authors: Lydia E. Belton; Elissa Z. Cameron; Fredrik Dalerum
      Pages: 13 - 23
      Abstract: Publication date: January 2018
      Source:Animal Behaviour, Volume 135
      Author(s): Lydia E. Belton, Elissa Z. Cameron, Fredrik Dalerum
      In group-living animals, the structure of social interactions among group members can have important consequences for individual fitness. Changes in resource abundance can influence social interactions with an expected weakening of social ties during times of resource scarcity. Although human activity and infrastructure often impose a disturbance on animal populations, they can also be a source of reliable resources that are relatively easy to access. We evaluated whether the social networks differed between four spotted hyaena, Crocuta crocuta, clans experiencing contrasting levels of human activity and infrastructure in the Kruger National Park, South Africa. The clan living in an area of high human activity and infrastructure had a less dense social network than the other clans, and the clan living in an area with limited human activity and infrastructure had shorter path lengths than the other clans, suggesting that it had more closely associated individuals. Our results did not support substantial differences between clans in the relative social network positions of animals from different age and rank classes. Contrary to our expectations, we suggest that anthropogenic resources may have weakened the social cohesiveness within spotted hyaena clans. We also argue that our study supports previous suggestions that there may be individual variation within broader classes of rank, age and sex in the position of individual animals in social networks.

      PubDate: 2017-12-12T02:10:15Z
      DOI: 10.1016/j.anbehav.2017.10.027
      Issue No: Vol. 135 (2017)
       
  • Lateralization of spontaneous behaviours in the domestic cat, Felis
           silvestris
    • Authors: Louise J. McDowell; Deborah L. Wells; Peter G. Hepper
      Pages: 37 - 43
      Abstract: Publication date: January 2018
      Source:Animal Behaviour, Volume 135
      Author(s): Louise J. McDowell, Deborah L. Wells, Peter G. Hepper
      Recent research has drawn attention to the link between lateral bias and cerebral functional asymmetry in animals. Most studies of animal laterality have focused on limb use arising from forced experimental challenges as opposed to spontaneous behaviours. This study explored, for the first time, the expression of lateralized spontaneous behaviour in the domestic cat, a species that exhibits motor bias in the form of paw preferences. The side used by 44 pet cats to perform three spontaneous behaviours (lying side, stepping down a flight of stairs, stepping over a raised object) was recorded. Paw preferences were also assessed using a more traditional forced food reaching challenge. Cats showed a significant lateral bias for food reaching, stepping down and stepping over. Those with a paw preference, however, did not differ significantly in their tendency towards left or right sidedness. The direction of the cats' side preferences was significantly correlated for most measures, whether forced or spontaneous. The strength of the cats' motor bias was significantly related to the task; animals displayed a weaker lateral bias for lying side than any other measure. The study revealed a sex split in the direction, although not the strength, of the cats' lateral bias for food reaching, stepping down and stepping over. Males showed a significant preference for using their left paw on these measures, while females were more inclined to use the right one. The study provides the first evidence that the domestic cat displays motor laterality on specific spontaneous behaviours, and that the direction, although not the strength, of these lateral biases is largely consistent with that of an experimental task. The results suggest that the more forced food-reaching test traditionally used to assess motor bias in the cat offers a biologically valid measure of limb use in this species.

      PubDate: 2017-12-12T02:10:15Z
      DOI: 10.1016/j.anbehav.2017.11.002
      Issue No: Vol. 135 (2017)
       
  • Thermal parental effects on offspring behaviour and their fitness
           consequences
    • Authors: Stephanie McDonald; Lisa E. Schwanz
      Pages: 45 - 55
      Abstract: Publication date: January 2018
      Source:Animal Behaviour, Volume 135
      Author(s): Stephanie McDonald, Lisa E. Schwanz
      Environmental and developmental conditions can drive substantial variation in offspring behaviour and developmental trajectory. While incubation temperature is well known to influence development in oviparous animals, little is known of the role of parental temperature on offspring phenotype (i.e. thermal parental effects). Following exposure of male and gravid female jacky dragons, Amphibolurus muricatus, to one of two thermal treatments (short-bask versus long-bask) and incubation of their eggs at a constant temperature, we examined whether the preovipositional parental treatment influenced offspring performance-related behaviours. We detected main and interactive effects of parental treatment on offspring behaviours including feeding, exploration and antipredator. Sex-specific effects of parental treatment included long-bask sons being more likely to feed and being bolder following predatory attack than short-bask sons, while the differences between treatments for daughters were smaller. Behaviours were not consistent between 1 week and 1 month of age and showed little correlation across behavioural contexts. Some behaviours emerged as promising mechanisms of documented parental effects on offspring growth and survival in these individuals. In particular, boldness among long-bask sons in an antipredator context may be linked to their greater rates of growth posthatching. Overall, our findings suggest that thermal parental effects influence variation in animal behaviours relevant for subsequent fitness outcomes.

      PubDate: 2017-12-12T02:10:15Z
      DOI: 10.1016/j.anbehav.2017.11.007
      Issue No: Vol. 135 (2017)
       
  • Susceptibility to ecological traps is similar among closely related taxa
           but sensitive to spatial isolation
    • Authors: Bruce A. Robertson; Isabel A. Keddy-Hector; Shailab D. Shrestha; Leah Y. Silverberg; Clara E. Woolner; Ian Hetterich; Gábor Horváth
      Pages: 77 - 84
      Abstract: Publication date: January 2018
      Source:Animal Behaviour, Volume 135
      Author(s): Bruce A. Robertson, Isabel A. Keddy-Hector, Shailab D. Shrestha, Leah Y. Silverberg, Clara E. Woolner, Ian Hetterich, Gábor Horváth
      Ecological traps are maladaptive behavioural scenarios in which animals prefer to settle in habitats with the lowest survival and/or reproductive success. Aquatic insect species, for example, are attracted to sources of horizontally polarized light associated with natural water bodies, but today they commonly prefer to lay their eggs upon asphalt roads and buildings that reflect an unnaturally high percentage of polarized light. Ecological traps are a rapidly emerging threat to the persistence of animal populations, but the degree to which species vary in their susceptibility to them remains uninvestigated. We designed a field experiment to (1) assess the relative susceptibility of aquatic flies (Diptera) to a single maladaptive behavioural cue: variation in degree of horizontally polarized light (d), and (2) quantify how the isolation of an ecological trap from a high-quality habitat affects its relative attractiveness. We exposed wild dipterans to experimental test surfaces varying in d at three distances from natural streams and mapped behavioural reaction norms of habitat preference as a function of d and distance from high-quality habitat. All seven of the dipteran families were captured most in traps with progressively higher d values, especially those (d =90–100%) that exceeded that of natural water bodies (30–80%). In most taxa, the height and slope of numerical responses to d were influenced by the distance of an ecological trap from a natural water body. Our results illustrate that dipterans have broadly evolved the use of a habitat selection behaviour that treats more strongly polarized light sources as indicative higher-quality habitats, making them broadly susceptible to ecological traps driven by polarized light pollution. We also found that the spatial isolation of ecological traps from higher-quality, but less attractive, habitats can either increase or reduce species' susceptibility to them.

      PubDate: 2017-12-12T02:10:15Z
      DOI: 10.1016/j.anbehav.2017.10.023
      Issue No: Vol. 135 (2017)
       
  • Differential effects of predator cues versus activation of fight-or-flight
           behaviour on reproduction in the cricket Gryllus texensis
    • Authors: S.A. Adamo; R. McKee
      Pages: 1 - 8
      Abstract: Publication date: December 2017
      Source:Animal Behaviour, Volume 134
      Author(s): S.A. Adamo, R. McKee
      How prey animals determine predation risk remains uncertain. We propose that one signal of high predation risk is repeated activation of fight-or-flight behaviour. We activated escape runs in the cricket Gryllus texensis by blowing air on the cerci. Escape runs were induced for 5min, three times per day, three times per week for 4 weeks. Repeated fight-or-flight behaviour led to a loss in mass and decreased life span, suggesting a decline in somatic maintenance. However, there was an increase in egg laying, which we interpret as terminal reproductive investment. Stress responses remained robust. Octopamine (OA), a stress neurohormone in insects, increased in concentration in the haemolymph after running, and the magnitude of the increase was the same even after repeated activation (i.e. there was no habituation of the response). There was also no increase in basal OA haemolymph levels. In a second experiment, crickets were exposed to a mantid (predator, Tenodera sinensis), a walking stick (nonpredator, Carausius morosus), or an empty container. None of the crickets exhibited fight-or-flight behaviour. However, mantid-exposed crickets decreased egg laying. There was no decrease in life span or mass. There was no change in basal levels of OA, or in the magnitude of the OA increase after running. These results are consistent with the hypothesis that repeated fight-or-flight behaviour induces reproductive responses that would be adaptive for a shortened life span. These responses differ from those produced by predator cues alone. Even short-lived animals, such as crickets, appear to alter reproduction depending on the relative predation risk and their residual reproductive potential.

      PubDate: 2017-11-11T14:35:15Z
      DOI: 10.1016/j.anbehav.2017.09.027
      Issue No: Vol. 134 (2017)
       
  • Male hyraxes increase countersinging as strangers become ‘nasty
           neighbours’
    • Authors: Yael Goll; Vlad Demartsev; Lee Koren; Eli Geffen
      Pages: 9 - 14
      Abstract: Publication date: December 2017
      Source:Animal Behaviour, Volume 134
      Author(s): Yael Goll, Vlad Demartsev, Lee Koren, Eli Geffen
      Many territorial animals interact less aggressively with neighbours than with strangers, a phenomenon known as the ‘dear enemy’ effect, although some species show the opposite behaviour. Rock hyraxes, Procavia capensis, are social mammals that communicate via a rich acoustic repertoire. Male hyraxes produce elaborate advertisement calls (i.e. songs) both spontaneously and in response to occasional attention-grabbing events (e.g. pup screams, agonistic interaction), as well as to conspecific male songs. When replying to conspecific songs, male hyraxes tend to respond more to familiar males than to strangers, reflecting the ‘nasty neighbour’ effect. Our study relates to the general question of why some species respond aggressively towards neighbours, while others are more aggressive towards strangers. We hypothesized that male hyraxes eventually familiarize themselves with a stranger, subsequently perceiving its intentions as highly threatening and deserving of a vocal response. To simulate the presence of a stranger in the area we exposed wild hyrax groups to playbacks of natural songs of unfamiliar hyraxes. Male rock hyraxes became more likely to reply to a stranger's song over time, but this was independent of the number of times they heard the song. This suggests that either (1) the threat presented by a stranger increases when it is no longer perceived as transient or (2) because listeners do not physically encounter the stranger, they perceive replying aggressively as a low-risk response. Our work implies that species may demonstrate a range of condition-dependent behaviours instead of a dichotomy between the ‘nasty neighbour’ and ‘dear enemy’ strategies.

      PubDate: 2017-11-11T14:35:15Z
      DOI: 10.1016/j.anbehav.2017.10.002
      Issue No: Vol. 134 (2017)
       
  • Juvenile coral reef fish alter escape responses when exposed to changes in
           background and acute risk levels
    • Authors: Ryan A. Ramasamy; Bridie J.M. Allan; Mark I. McCormick; Douglas P. Chivers; Matthew D. Mitchell; Maud C.O. Ferrari
      Pages: 15 - 22
      Abstract: Publication date: December 2017
      Source:Animal Behaviour, Volume 134
      Author(s): Ryan A. Ramasamy, Bridie J.M. Allan, Mark I. McCormick, Douglas P. Chivers, Matthew D. Mitchell, Maud C.O. Ferrari
      The response of prey to predation threats is often plastic and can vary with the individual's perceived level of threat. To determine whether prey escape responses can be modulated by background levels of risk or short-term acute risk, we maintained juvenile damselfish, Acanthochromis polyacanthus, under high- or low-risk background conditions for several days and then exposed them to an acute risk (high-risk alarm cues or a low-risk saltwater control) minutes prior to startling them with a mechanical disturbance. Fish responded in one of two ways: they either made a C-start escape response or backed away from the threat. While exposure to either background high risk or acute high risk increased the proportion of C-starters, surprisingly the frequency of C-starters decreased when background high risk and acute risk types were combined. Exposure to an acute high-risk cue increased the escape performance for both types of escape responses. However, when the acute high-risk cue occurred within high-risk background conditions, this only increased the performance of C-start escape responses. Non-C-starters reacted similarly in both background risk conditions. Background risk and acute risk acted in a simple additive manner, as seen by the lack of interaction between the two factors. Results showed that escape responses are amplified as the level of perceived risk increases.

      PubDate: 2017-11-11T14:35:15Z
      DOI: 10.1016/j.anbehav.2017.09.026
      Issue No: Vol. 134 (2017)
       
  • Climatic, social and reproductive influences on behavioural
           thermoregulation in a female-dominated lemur
    • Authors: Timothy M. Eppley; Julia Watzek; Katie Hall; Giuseppe Donati
      Pages: 25 - 34
      Abstract: Publication date: December 2017
      Source:Animal Behaviour, Volume 134
      Author(s): Timothy M. Eppley, Julia Watzek, Katie Hall, Giuseppe Donati
      It is well established that social rank in a large group confers a higher adaptive value to a dominant individual relative to others, although there is scant evidence that members of small social groups either have similar social standing or maintain strict dominance. We aimed to determine whether members of small social groups, using the southern bamboo lemur, Hapalemur meridionalis, as a model, gain rank-related benefits. We first established a dominance hierarchy through a network-based analysis of win–loss interactions, which showed that adult females maintained social dominance within their groups, similar to many strepsirrhine species. To address whether dominant individuals gained rank-related benefits, we then explored how social dynamics may permit access to resting huddles, which provide a physiological benefit. Social thermoregulation, i.e. huddling, is a behavioural energy conservation mechanism, and among many mammals is a direct response to decreasing ambient temperatures. As such, huddling behaviour may have evolved among social animals because of its potential direct and indirect benefits. To examine the effect of dominance rank within small social groups on huddling inclusion, we used generalized linear mixed-effects models to predict the likelihood of huddling occurring during resting bouts from climatic (e.g. temperature, precipitation), social (e.g. affiliation, dominance rank, grooming) and reproductive (e.g. access, infant protection) variables. We found that lower temperatures, especially during shorter resting bouts, increased the likelihood of huddling. Grooming between partners with a high discrepancy in rank increased huddling. Additionally, huddling increased during the reproductive season, potentially offering greater opportunity for males to gain favour with sexually receptive females, and when new-borns were present, providing essential thermal maintenance and potential antipredator protection to infants. Together, our results suggest that even in small social groups, females gain rank-related benefits by controlling access to huddles, i.e. the intrinsic benefits of social thermoregulation.

      PubDate: 2017-11-11T14:35:15Z
      DOI: 10.1016/j.anbehav.2017.10.003
      Issue No: Vol. 134 (2017)
       
  • Incubation onset maintains survival of most embryos and growth and
           survival of late-hatched young
    • Authors: Robert A. Aldredge
      Pages: 35 - 43
      Abstract: Publication date: December 2017
      Source:Animal Behaviour, Volume 134
      Author(s): Robert A. Aldredge
      Hatching asynchrony occurs primarily as a consequence of the timing of embryonic development. Despite over 50 years of study, it is unclear why, ultimately, most birds initiate embryonic development (incubation) before all eggs are laid. One hypothesis focuses on prehatching (embryo) survival and predicts that early incubation maximizes embryo survival by reducing exposure of unincubated eggs (egg viability hypothesis). Another set of hypotheses focuses on posthatching growth and survival and predicts that females time incubation to maximize the number or quality of hatched offspring that fledge (adaptive hatching pattern hypotheses). I experimentally manipulated when females could begin incubation to test how timing of embryonic development influences prehatching survival and posthatching growth and survival in the house sparrow, Passer domesticus. Despite high embryo survival in both naturally asynchronous and experimentally synchronized nests, early incubation appeared to maximize embryo survival in all but the earliest-laid eggs, suggesting that house sparrows begin incubation too late to maximize survival of all embryos. Early incubation had little effect on overall (i.e. mean) patterns of posthatching growth and survival. However, early incubation increased the initial variation in offspring size because last-hatched young were relatively small when all eggs had completed hatching. Nestlings that were small at hatch completion grew slowly and exhibited a reduced probability of survival, suggesting that house sparrows begin incubation too early to maximize growth and survival of hatched offspring. These results suggest that timing of incubation neither maximizes embryo survival nor maximizes posthatching growth and survival. Instead, early incubation appears to be a trade-off between maintaining both embryo survival and growth and survival of late-hatched offspring. Thus, house sparrow females likely time incubation as an adaptive strategy to maximize the number of embryos that survive the incubation and nestling periods to fledge.

      PubDate: 2017-11-11T14:35:15Z
      DOI: 10.1016/j.anbehav.2017.09.022
      Issue No: Vol. 134 (2017)
       
  • Pesticide-induced changes in personality depend on the urbanization level
    • Authors: Nedim Tüzün; Selina Müller; Kamilla Koch; Robby Stoks
      Pages: 45 - 55
      Abstract: Publication date: December 2017
      Source:Animal Behaviour, Volume 134
      Author(s): Nedim Tüzün, Selina Müller, Kamilla Koch, Robby Stoks
      Globally increasing urbanization causes major anthropogenic changes in ecosystems, drastically altering phenotypes of organisms. Increased contamination is a well-known result of urbanization, and its effect on behaviour has been extensively studied. Yet, animal personality, consistent behavioural variation between individuals, has rarely been investigated in the context of anthropogenic contaminants. Changes in personalities may affect the viability of populations, and even alter community dynamics. We investigated the effects of exposure to a sublethal dose of the commonly used pesticide esfenvalerate on two personality traits, activity and boldness, and compared these effects between replicated rural and urban populations using larvae of the damselfly Coenagrion puella. We tested for effects on behaviour at three distinct levels: the average levels of behaviours, the consistency of behaviours (repeatability), and the structure of the behavioural correlations (behavioural syndrome). We found that the pesticide treatment changed the average activity and the behavioural covariation (activity and boldness), but not the behavioural repeatability. Importantly, these pesticide-induced patterns depended strongly on urbanization level. The average activity reduction due to pesticide exposure was only present in urban individuals. Moreover, while a behavioural correlation between activity and boldness in rural larvae appeared only after the pesticide treatment, this activity–boldness syndrome was consistently present in the urban larvae. These differential responses of urban and rural populations may be explained by the apparently more efficient coping mechanism with contaminants of urban populations, as well as the generally more stressful urban habitats. These results highlight the importance of measuring behavioural expressions at various levels when assessing contaminant effects, and not just the means. Further, we suggest that pollution may play an important role in understanding the evolution and maintenance of animal personalities in natural populations.

      PubDate: 2017-11-11T14:35:15Z
      DOI: 10.1016/j.anbehav.2017.10.007
      Issue No: Vol. 134 (2017)
       
  • Curiosity boosts orang-utan problem-solving ability
    • Authors: Laura A. Damerius; Sereina M. Graber; Erik P. Willems; Carel P. van Schaik
      Pages: 57 - 70
      Abstract: Publication date: December 2017
      Source:Animal Behaviour, Volume 134
      Author(s): Laura A. Damerius, Sereina M. Graber, Erik P. Willems, Carel P. van Schaik
      Investigating the mechanisms underlying individual variation in cognitive performance is a crucial step towards understanding the structure and evolution of cognition. In this study, we investigated phenotypic plasticity of 61 Bornean, Pongo pygmaeus, and Sumatran, Pongo abelii, orang-utans to gain insight into how rearing history shapes problem-solving approaches. We first examined the determinants of an individual's response-and-exploration style, which we assessed using five independent novelty response and exploration tasks. Our findings revealed that both previous care by humans and social housing with conspecifics elicited a curious response-and-exploration style (characterized by a positive response to novelty and a high motivation to explore). Second, we investigated how the response-and-exploration style and previous experiences affected an individual's problem-solving performance in a variety of tasks aimed at assessing physical cognition, including reversal learning, inhibitory control, causal reasoning and tool use. We found curiosity to be the sole predictor of problem-solving performance. However, curiosity is strikingly rare in wild orang-utans, being mainly induced by contact with humans and living in a safe and stimulating physical and social environment. We therefore suggest that curiosity in orang-utans is an artefact of captivity, a potential only expressed under special conditions. The origin of curiosity in our own lineage may have been an important contributor to the rapid rise in the complexity of our ancestors' material culture.

      PubDate: 2017-11-11T14:35:15Z
      DOI: 10.1016/j.anbehav.2017.10.005
      Issue No: Vol. 134 (2017)
       
  • Female kin density affects offspring sex ratio in an asocial mammal, the
           golden-mantled ground squirrel, Callospermophilus lateralis
    • Authors: C.P. Wells; D.H. Van Vuren
      Pages: 71 - 77
      Abstract: Publication date: December 2017
      Source:Animal Behaviour, Volume 134
      Author(s): C.P. Wells, D.H. Van Vuren
      Evolutionary theory predicts that parents should bias investment in offspring towards the sex that will yield the higher fitness returns, and one outcome may be biased offspring sex ratios. Bias in offspring sex ratios has been proposed to vary with specific social, maternal and environmental conditions that alter the fitness returns of each sex, but empirical evidence is conflicting both within and across taxa. We used 18 years of pedigree and demographic data to investigate variation in offspring sex ratios in a population of golden-mantled ground squirrels. Despite overall parity in offspring sex ratio, we found predictable changes in offspring sex ratio in response to female density at the population level: squirrels produced more daughters when female density was low and more sons when female density was high. At the individual level, females adjusted litter sex ratios similarly, but only in response to high densities of kin, and not in response to density of nonkin. This effect was reversed for older females (≥3 years) in dense kin neighbourhoods, which were more likely to produce daughters, perhaps because older females had the behavioural dominance necessary to recruit daughters at high densities. By contrast, litter sex ratios did not vary with maternal condition or food availability. Our results support the local resource competition theory of offspring sex allocation for this species. Knowledge of female relatedness revealed patterns of sex ratio adjustment that otherwise would have been obscured, highlighting the importance of interactions with kin in an asocial species.

      PubDate: 2017-11-11T14:35:15Z
      DOI: 10.1016/j.anbehav.2017.10.004
      Issue No: Vol. 134 (2017)
       
  • Social security: are socially connected individuals less vigilant'
    • Authors: Rachael P. Mady; Daniel T. Blumstein
      Pages: 79 - 85
      Abstract: Publication date: December 2017
      Source:Animal Behaviour, Volume 134
      Author(s): Rachael P. Mady, Daniel T. Blumstein
      Group size effects, whereby animals allocate less time to antipredator vigilance as a function of increasing numbers of animals foraging together, are reported in many taxa, but group size is but one of many social attributes that could increase an individual's perception of predation risk or what might be referred to as a ‘sense of security’. Indeed, meta-analyses suggest that group size only explains a small amount of variation in vigilance, and studies have shown that other social attributes, such as dominance status, also influence perceived risk and time allocated to vigilance. Social network analysis is an emerging technique to quantify a variety of specific social attributes, some of which have been suggested to influence ‘security’. Using the proportion of time looking as an indicator of vigilance and predation risk assessment, we tested the prediction that more socially connected yellow-bellied marmots, Marmota flaviventer, look less while foraging compared to their less socially connected counterparts. For females and males separately, we used observational data to create intrasexual, weighted social networks. We used principal component analysis to reduce correlated measures to unrelated and independent descriptions of connectedness. Using linear mixed effect models to account for potentially confounding variables, we found that no social network measure explained variation in vigilance. Social group size explained variation in female vigilance after accounting for variation due to vegetation height and date. Foraging group size and vegetation height explained variation in male vigilance. While social network measures themselves were not significant, our results mirror the fact that yellow-bellied marmots live in female-dominated societies and suggest that overall social group size is relatively more important for females than for males. Systematically studying whether and how social factors and intrasexual social relationships influence antipredator behaviour in other animals will create a better understanding of the benefits of sociality.

      PubDate: 2017-11-11T14:35:15Z
      DOI: 10.1016/j.anbehav.2017.10.010
      Issue No: Vol. 134 (2017)
       
  • Gastrointestinal parasitism and recursive movements in free-ranging
           mandrills
    • Authors: Clémence Poirotte; Simon Benhamou; Andrela Mandjembe; Eric Willaume; Peter M. Kappeler; Marie J.E. Charpentier
      Pages: 87 - 98
      Abstract: Publication date: December 2017
      Source:Animal Behaviour, Volume 134
      Author(s): Clémence Poirotte, Simon Benhamou, Andrela Mandjembe, Eric Willaume, Peter M. Kappeler, Marie J.E. Charpentier
      Understanding animal movements is a key prerequisite for deciphering ecological processes such as population dynamics, community structure or biological invasions. Many animals restrict their movements to certain areas (home ranges) by alternating visits among several suitable sites. The dynamics of these recursive movements are assumed to be primarily driven by food availability and predation risk. In contrast, environmental parasite pressures have rarely been considered as possible drivers of animals' ranging patterns. In this article, we present evidence that environmentally transmitted gastrointestinal parasites may shape recursive movement patterns of a group of free-ranging mandrills, Mandrillus sphinx. These rainforest-dwelling primates returned less frequently and after longer time lags to sites, including sleeping sites, they had contaminated than to sites with low contamination levels. This pattern was especially pronounced during the dry season, when contamination risk was highest. In contrast, rainfall shortened the time between visits, consistent with the hypothesis that rainfall may wash away parasites, allowing a more rapid return to previously used sites. Although resource distribution and predator threat could not be ruled out in this study, we suggest that the risk of acquiring environmentally transmitted parasites is possibly another factor influencing animal ranging patterns as well as habitat selection or species distribution. Consequently, parasites and their distribution in the environment, as well as the possible antiparasite strategy we document here, should be targets for future research on animal movement.

      PubDate: 2017-11-11T14:35:15Z
      DOI: 10.1016/j.anbehav.2017.10.013
      Issue No: Vol. 134 (2017)
       
  • Multimodal weighting differences by bats and their prey: probing natural
           selection pressures on sexually selected traits
    • Authors: D.G.E. Gomes; W. Halfwerk; R.C. Taylor; M.J. Ryan; R.A. Page
      Pages: 99 - 102
      Abstract: Publication date: December 2017
      Source:Animal Behaviour, Volume 134
      Author(s): D.G.E. Gomes, W. Halfwerk, R.C. Taylor, M.J. Ryan, R.A. Page
      Multimodal communication has received increasing attention in recent years. While much is understood about how intended receivers (such as potential mates) respond to multimodal displays, less is known about how eavesdropping predators perceive and interpret these cues. The male túngara frog, Physalaemus pustulosus, is a neotropical anuran that attracts females with an acoustic call and a dynamically inflating/deflating vocal sac. However, the túngara frog's multimodal courtship display also attracts eavesdropping predators, such as fringe-lipped bats, Trachops cirrhosus. We utilized robotic frog models to expose fringe-lipped bats to multimodal túngara frog courtship displays. The models varied in call amplitude and/or the presence of vocal sac cues. In a two-choice test, we show that fringe-lipped bats more often attack higher-amplitude calls. Additionally, coupling the inflating vocal sac cues to the lower-amplitude frog call increased the probability that a bat would attack this less attractive call. Previous studies have demonstrated that vocal sac cues do not increase the attractiveness of low-amplitude calls to female P. pustulosus. Thus, although natural selection, through the bats, and sexual selection, through the female frogs, exert counter-selection forces on the male's sexual display, the strength of these forces are not symmetrical. We discuss possible explanations for why this might be the case. This study underlines the importance of understanding the contribution of both intended and unintended receivers on signal evolution, and it helps explain how selection pressures might vary across sensory modalities.

      PubDate: 2017-11-11T14:35:15Z
      DOI: 10.1016/j.anbehav.2017.10.011
      Issue No: Vol. 134 (2017)
       
  • Individual and demographic consequences of mass eviction in cooperative
           banded mongooses
    • Authors: Faye J. Thompson; Harry H. Marshall; Emma I.K. Vitikainen; Andrew J. Young; Michael A. Cant
      Pages: 103 - 112
      Abstract: Publication date: December 2017
      Source:Animal Behaviour, Volume 134
      Author(s): Faye J. Thompson, Harry H. Marshall, Emma I.K. Vitikainen, Andrew J. Young, Michael A. Cant
      In animal societies, conflict within groups can result in eviction, where individuals are often permanently expelled from their group. To understand the evolution of eviction and its role in the resolution of within-group conflict requires information on the demographic consequences of eviction for individuals and groups. However, such information is usually difficult to obtain because of the difficulty in tracking and monitoring individuals after they are evicted from their natal groups. Here we used a 15-year data set on life history and demography to investigate the consequences of eviction in a tractable cooperatively breeding mammal, the banded mongoose, Mungos mungo. In this species, groups of individuals are periodically evicted en masse and eviction is a primary mechanism by which new groups form in the study population. Following eviction, we found sex differences in dispersal distance: some females established new groups on the study peninsula but males always dispersed away from the study peninsula. Evicted females suffered reduced reproductive success in the year after eviction. For the evicting group, eviction was associated with increased per capita reproductive success for females, suggesting that eviction is successful in reducing reproductive competition. However, eviction was also associated with increased intergroup conflict for the evicting group. Our results suggest that within-group conflict resolution strategies affect group productivity, group interactions and the structure of the population, and hence have fitness impacts that reach beyond the individual evictors and evictees involved in eviction.

      PubDate: 2017-11-20T14:26:17Z
      DOI: 10.1016/j.anbehav.2017.10.009
      Issue No: Vol. 134 (2017)
       
  • Eavesdropping avoidance and sound propagation: the acoustic structure of
           soft song
    • Authors: Luis E. Vargas-Castro; Luis Sandoval; William A. Searcy
      Pages: 113 - 121
      Abstract: Publication date: December 2017
      Source:Animal Behaviour, Volume 134
      Author(s): Luis E. Vargas-Castro, Luis Sandoval, William A. Searcy
      Many species use low-amplitude (soft) song during close range interactions with conspecifics, such as in aggressive encounters or courtship displays. It has been suggested that soft song is adapted to limit eavesdropping by conspecifics or predators through reduced signal transmission range. If so, other structural features of soft song, besides amplitude, should be adapted to reduce transmission. The soft songs of white-throated thrushes, Turdus assimilis, have properties expected to lower transmission, such as higher frequency and broader bandwidth relative to broadcast songs. We compared the transmission properties of broadcast and soft syllables using a sound propagation field experiment. When played at the same amplitude as broadcast song, soft song showed greater excess attenuation and blur ratios and lower signal-to-noise ratios. Lowering the frequency of soft syllables recovered similar transmission properties as those of broadcast syllables. Further analysis of spectral traits showed that excess attenuation values were mainly affected by minimum frequency and peak frequency, while blur ratio variation was predominantly affected by bandwidth, and signal-to-noise ratios were predicted by bandwidth and peak frequency. Additionally, soft song had more frequency overlap with background noise than broadcast song. These results support the eavesdropping hypothesis: aspects of the acoustic structure of soft signals in addition to low amplitude seem to have been shaped by selection to reduce transmission and avoid eavesdroppers.

      PubDate: 2017-11-20T14:26:17Z
      DOI: 10.1016/j.anbehav.2017.10.008
      Issue No: Vol. 134 (2017)
       
  • Influence of dietary nutrient balance on aggression and signalling in male
           field crickets
    • Authors: Sarah J. Harrison; Jean-Guy J. Godin; Susan M. Bertram
      Pages: 123 - 134
      Abstract: Publication date: December 2017
      Source:Animal Behaviour, Volume 134
      Author(s): Sarah J. Harrison, Jean-Guy J. Godin, Susan M. Bertram
      Indicator models of sexual selection predict that sexually selected trait elaboration should covary positively with condition. However, nutrition might influence the expression of multiple traits, where high-quality diets may result in positive trait correlations and low-quality diets in trade-offs. Although previous studies have examined how diet quantity or single nutrients, such as protein, carbohydrate and phosphorus, influence sexual traits, few have examined how dietary nutrient balance affects sexual trait expression. We therefore investigated how dietary protein:carbohydrate ratio and percentage of phosphorus influence the relationship between investment in mate attraction signalling and aggression. We fought groups of six adult male Gryllus veletis crickets, each consuming a unique diet, while recording their prefight and postfight signalling parameters. We found no evidence that diet influenced aggression or prefight signalling, with the exception that high-phosphorus diets had a negative influence on several signalling effort parameters. Body size was an important predictor of aggressive behaviour and most signalling parameters, suggesting that developmental diet may have a greater influence on these sexual traits. Several prefight signalling parameters were weakly related to aggression, suggesting that signalling may advertise competitive abilities. Males consuming high-carbohydrate and equal protein:carbohydrate diets experienced changes in signalling parameters that represented an overall increase in signalling effort following aggressive contests compared to males consuming high-protein diets, suggesting that dietary effects on signalling may only become apparent following periods of highly energetic activity. Changes in signalling following aggressive contests were also related to aggression levels modulated by dietary phosphorus content, such that only males consuming low-phosphorus diets were able to invest heavily in signalling after investing heavily in aggression. Our findings highlight the importance of research on the interplay between multiple sexually selected traits, and how dietary nutrient balance influences these relationships.

      PubDate: 2017-11-20T14:26:17Z
      DOI: 10.1016/j.anbehav.2017.10.006
      Issue No: Vol. 134 (2017)
       
  • Seasonal variation in female Asian elephant social structure in
           Nagarahole-Bandipur, southern India
    • Authors: S. Nandini; P. Keerthipriya; T.N.C. Vidya
      Pages: 135 - 145
      Abstract: Publication date: December 2017
      Source:Animal Behaviour, Volume 134
      Author(s): S. Nandini, P. Keerthipriya, T.N.C. Vidya
      Fission–fusion dynamics allow for individuals to deal with spatiotemporally changing food resources, with groups from a community fusing together when resources are abundant and splitting away when competition for resources is high. Such fission–fusion dynamics are often modulated by seasonal changes in resources. We examined the seasonal variation in group size and social structure of female Asian elephants, which show high fission–fusion dynamics, in a population in southern India. Females in this population form many distinct communities or clans in both the dry and wet seasons. At the population level, females were sighted in larger group sizes and associated with more uncommon females in the dry season. However, when associations among common females were considered, a greater number of stronger associations were observed in the wet season. There were no consistently significant seasonal differences in group sizes or associations at the clan level. Thus, population-level results, obtained by a combination of results from different clans, may sometimes be misleading. Female associations showed some temporal stability, with association indices being moderately correlated across consecutive seasons and years. Interestingly, average group sizes were similar across clans of different sizes, indicating a restriction on group size, possibly due to resource distribution. In spite of this restriction, most clan-mates showed low, non-zero associations amongst themselves rather than very strong associations with a small set of individuals. The resulting fluid rather than fixed groups suggest a benefit to socializing with other clan-mates. Thus, unlike the pattern usually seen, fission–fusion dynamics here is a means to maintain multiple associates under conditions of relatively constant but constrained group size, rather than being a means of increasing or decreasing group size in response to ecological factors.

      PubDate: 2017-11-20T14:26:17Z
      DOI: 10.1016/j.anbehav.2017.10.012
      Issue No: Vol. 134 (2017)
       
  • Birds choose long-term partners years before breeding
    • Authors: Claire S. Teitelbaum; Sarah J. Converse; Thomas Mueller
      Pages: 147 - 154
      Abstract: Publication date: December 2017
      Source:Animal Behaviour, Volume 134
      Author(s): Claire S. Teitelbaum, Sarah J. Converse, Thomas Mueller
      Pair bonds can provide social benefits to long-term monogamous species alongside their benefits for reproduction. However, little is known about when these bonds form, in particular how long they are present before breeding. Previous studies of pair formation in long-term monogamous birds have been rather data-limited, but for many migratory birds they report pair formation on the wintering grounds. We provide the first systematic investigation of prebreeding association patterns of long-term monogamous pairs by examining entire life histories based on tracking data of migratory whooping cranes, Grus americana. We found that a substantial portion (62%) of breeding pairs started associating at least 12 months before first breeding, with 16 of 58 breeding pairs beginning to associate over 2 years before first breeding. For most pairs, these associations with future breeding partners also became unique and distinguishable from association patterns with nonpartner individuals 12 months before first breeding. In addition, 60% of pair associations began before at least one partner had reached nominal sexual maturity. Most pairs began associating in the late spring upon arrival at the summer grounds, while associations beginning at other times of the year were rare. Patterns in the associations of pairs prior to breeding can point to the potential benefits of prebreeding relationships, for instance providing support in competitive interactions or increasing partner familiarity.

      PubDate: 2017-11-20T14:26:17Z
      DOI: 10.1016/j.anbehav.2017.10.015
      Issue No: Vol. 134 (2017)
       
  • The influence of demographic variation on social network stability in wild
           vervet monkeys
    • Authors: Christèle Borgeaud; Sebastian Sosa; Cédric Sueur; Redouan Bshary
      Pages: 155 - 165
      Abstract: Publication date: December 2017
      Source:Animal Behaviour, Volume 134
      Author(s): Christèle Borgeaud, Sebastian Sosa, Cédric Sueur, Redouan Bshary
      From a cognitive point of view, management and knowledge of social relationships is thought to be very challenging. Because of ecological and demographic constraints, relationships are likely to be prone to variation and hence need constant updating. Social network analysis is a potential tool to quantify the information that needs to be processed. However, despite the growing number of studies on social networks, few have focused on their dynamics and how they evolve across time. Here we present one of the rare studies that tests the influence of demographic variation on social relationships' stability through temporal analysis. Using field data collected on three wild groups of vervet monkeys, Chlorocebus aethiops, we first analysed the relationships' stability by running correlations between 3-month periods. Then, we investigated how natural demographic variation changed individual centralities (eigenvector) and strength of dyadic relationships within both grooming and proximity networks over a period of 2 years. In vervets, females are philopatric, while males emigrate from their natal group. Thus, we tested whether changes in demography had more influence on network centrality measures and relationship strength in females and their juveniles than in males. Correlations between periods yielded no evidence that predictability of future relationship quality declined with time from current relationship quality. In addition, male immigration was mostly responsible for increases in the core group members' centrality while male emigration had the opposite effect. Regarding dyadic relationships, we found inconsistent patterns that varied with respect to how age/sex and immigration/disappearance affected the network studied (grooming versus proximity). Our findings support the idea that social networks are dynamic structures that vary through time. Similar analyses on other species are needed to investigate which network features emerge as candidates responsible for variation in the complexity with which individuals keep track of relationships.

      PubDate: 2017-11-20T14:26:17Z
      DOI: 10.1016/j.anbehav.2017.09.028
      Issue No: Vol. 134 (2017)
       
  • Intraseasonal temporal variation of reproductive effort for male grey
           seals
    • Authors: Amanda M. Bishop; James E. Stewart; Patrick Pomeroy; Sean D. Twiss
      Pages: 167 - 175
      Abstract: Publication date: December 2017
      Source:Animal Behaviour, Volume 134
      Author(s): Amanda M. Bishop, James E. Stewart, Patrick Pomeroy, Sean D. Twiss
      Reproductive skew in polygynous mating systems leads to variation in mating strategies, or the tactics within strategies, adopted by individual males. For example, variation in the timing of reproductive effort might reflect trade-offs between maximizing access to receptive females and minimizing interactions with competitors. For capital breeding grey seals, Halichoerus grypus, male mating success has been positively linked to total duration of tenure, but without differentiation of intraseasonal changes in reproductive effort. The aims of this study were to identify tactics within the tenured male strategy based on the timing of social dominance as a metric of reproductive effort, and to compare mating success across identified tactics. Our results confirm that duration of stay on the colony explained the most variation in mating success, but effect strength was reduced for tenures longer than 10 days. Additionally, there was evidence that timing of reproductive effort within a breeding season also contributed to observed variation in mating success. Males that maximized their dominance score at or after the peak in female attendance achieved greater mating success, relative to those who were dominant earlier in the breeding season. Males who timed their reproductive effort earlier in the season still achieved some mating success, but it was reduced. Individuals' tactics were flexible across years, and we found no evidence to support the hypotheses that timing of reproductive effort before or after the peak in female attendance was used by smaller tenured males, or to avoid conflict. These results highlight that understanding temporal scheduling of individual reproductive effort within a breeding season, relative to the availability of resources, constraints of fasting and intermale competition, is a key aspect to consider when differentiating individual tactics in long-lived, capital polygynous breeders.

      PubDate: 2017-12-01T12:09:08Z
      DOI: 10.1016/j.anbehav.2017.10.021
      Issue No: Vol. 134 (2017)
       
  • Leadership through knowledge and experience in a social sawfly
    • Authors: Lisa K. Hodgkin; Matthew R.E. Symonds; Mark A. Elgar
      Pages: 177 - 181
      Abstract: Publication date: December 2017
      Source:Animal Behaviour, Volume 134
      Author(s): Lisa K. Hodgkin, Matthew R.E. Symonds, Mark A. Elgar
      Leaders in democratic societies emerge by dint of followers, but the traits that determine who those leaders are, and the underlying mechanisms maintaining leadership, remain largely unknown. Models suggest a link between leadership and knowledge is important for group decisions, with more informed individuals guiding the uninformed majority. In larval aggregations of the Australian steel blue sawfly, Perga affinis, some individuals consistently lead the group on foraging trips more frequently than expected by chance. We manipulated both social group composition and the environment to determine in what circumstances leaders were retained within the aggregation. Leaders only resumed guiding group movement when they were familiar with (i.e. had knowledge of) the environment, a role they undertook even among unknown conspecifics. However, knowledgeable followers did not lead naïve aggregations. These results emphasize the importance of knowledge and prior experience in maintaining the leadership role within larval aggregations.

      PubDate: 2017-12-01T12:09:08Z
      DOI: 10.1016/j.anbehav.2017.10.017
      Issue No: Vol. 134 (2017)
       
  • Extrapair fertilizations vary with female traits and pair composition,
           besides male attractiveness, in barn swallows
    • Authors: Alessandra Costanzo; Roberto Ambrosini; Manuela Caprioli; Emanuele Gatti; Marco Parolini; Andrea Romano; Diego Rubolini; Luca Gianfranceschi; Nicola Saino
      Pages: 183 - 191
      Abstract: Publication date: December 2017
      Source:Animal Behaviour, Volume 134
      Author(s): Alessandra Costanzo, Roberto Ambrosini, Manuela Caprioli, Emanuele Gatti, Marco Parolini, Andrea Romano, Diego Rubolini, Luca Gianfranceschi, Nicola Saino
      Reproductive promiscuity, whereby females are fertilized by extrapair mates, is common. The frequency of extrapair fertilizations (EPFs) depends on at least three sources of variation. First, females may differ in their proneness to being fertilized by extrapair males. Second, males may differ in traits that affect realized promiscuity of females. Third, EPF decisions depend on the combined effects of the identity of social mates. Here, we relied on extensive genetic parentage analysis of the offspring of a socially monogamous bird, the barn swallow, Hirundo rustica, to assess which of the above sources of variation predict the occurrence of EPFs. When we controlled for pair composition and social mate attractiveness, EPFs covaried with morphological and coloration traits of feathers in females. As expected, females mated with highly ornamented, long-tailed males had fewer EPFs. The composition of the breeding pair also accounted for variation in EPFs, implying that the ability of individual males to secure genetic parentage varies between female mates. These results show that females differ in promiscuity, and phenotypic traits of females that are visible to males are associated with promiscuity, potentially serving as cues to prospecting males. Hence, contrary to common interpretations of the negative relationship between male sexual attractiveness and female promiscuity, it can be speculated that larger genetic parentage by highly ornamented males results from their ability to secure the less promiscuous mates rather than from females being less promiscuous when mated to them. Moreover, our study shows that EPFs also depend on the composition of the social pair, as expected if a component of female promiscuity decisions depends on genetic or behavioural compatibility with the social male mate. Our study emphasizes that female promiscuity and its phenotypic correlates, and composition of the social pair, deserve closer attention in studies of sexual selection mediated by EPFs.

      PubDate: 2017-12-01T12:09:08Z
      DOI: 10.1016/j.anbehav.2017.10.019
      Issue No: Vol. 134 (2017)
       
  • Do rhesus macaques, Macaca mulatta, understand what others know when gaze
           following'
    • Authors: Lindsey A. Drayton; Laurie R. Santos
      Pages: 193 - 199
      Abstract: Publication date: December 2017
      Source:Animal Behaviour, Volume 134
      Author(s): Lindsey A. Drayton, Laurie R. Santos
      A basic tendency to look where others are looking provides animals with the opportunity to learn about important objects in the environment, such as the location of conspecifics, food and predators. Although research has shown that many social species are able to follow others' gaze, the extent to which different species rely on sophisticated cognitive capacities when gaze following is debated. Whereas some species follow gaze via a relatively inflexible orienting response, gaze following in other species may reflect a deeper understanding of the visual perspective and attentional states of agents. Identifying the mechanisms underlying gaze following in different species is the critical first step to addressing the challenging ultimate question of why different species vary in their gaze-following skills. Therefore, we explored whether rhesus macaques have a mentalistic understanding of gaze. Specifically, we tested whether rhesus macaques are able to incorporate representations of a partner's knowledge state into their gaze-following response. In our study, macaques saw a human actor look to a distant location in a surprised manner. We manipulated whether or not the actor had previously seen the very first object in his line of sight. We found that monkeys looked for an alternative target of the actor's gaze more quickly when the actor had previously seen the object compared to when he had not. This suggests that rhesus macaques may have a mentalistic understanding of gaze cues.

      PubDate: 2017-12-01T12:09:08Z
      DOI: 10.1016/j.anbehav.2017.10.016
      Issue No: Vol. 134 (2017)
       
  • Egg size, begging behaviour and offspring fitness in Nicrophorus
           vespilloides
    • Authors: M.I. Mäenpää; P.T. Smiseth
      Pages: 201 - 208
      Abstract: Publication date: December 2017
      Source:Animal Behaviour, Volume 134
      Author(s): M.I. Mäenpää, P.T. Smiseth
      Egg size reflects the amount of energy that female parents have invested in their offspring prior to hatching, and is thus often used as a proxy for prehatching investment. According to life history theory, prehatching investment, in turn, trades off with posthatching investment, as the amount of resources allocated at the prehatching stage diminishes the resources available at the posthatching stage. As small eggs have smaller energy reserves than large eggs, the offspring originating from small eggs may have higher hunger levels, and thus beg more, offering the parents information about the need for more posthatching care. However, little is known about the relationship between egg size and begging behaviour, and the fitness correlates of the two. In this study, we directly investigated the association between these two traits in the burying beetle Nicrophorus vespilloides. Concurrently, we examined the effects of egg size on two components of offspring fitness: offspring growth and survival. We found no association between egg size and offspring begging behaviour. Egg size did, however, show a mostly positive, albeit indirect, association with offspring fitness traits (development time, size and survival). Therefore, an increase in egg size does have an impact on offspring fitness, but this impact is not mediated through offspring begging. To our knowledge, this is the first time the relationship between egg size and begging behaviour has been investigated directly.

      PubDate: 2017-12-01T12:09:08Z
      DOI: 10.1016/j.anbehav.2017.10.014
      Issue No: Vol. 134 (2017)
       
  • Flight speed adjustment by three wader species in relation to winds and
           flock size
    • Authors: Anders Hedenström; Susanne Åkesson
      Pages: 209 - 215
      Abstract: Publication date: December 2017
      Source:Animal Behaviour, Volume 134
      Author(s): Anders Hedenström, Susanne Åkesson
      The selection of flight speed (airspeed) in migrating birds depends on multiple internal and external factors, such as wing morphology, weight and winds. Adjustment with respect to side winds to maintain an intended track direction may include a shift in heading direction and/or an increase in airspeed. Compensation for cross-winds cannot always be achieved if visual references are lacking or may not even be beneficial if adaptive wind drift is favourable. Flock size is an additional, although often neglected, factor that could influence the airspeed of birds. Here, we show that responses to cross-winds to achieve compensation differed on a small geographical scale (a few kilometres) in migrating shorebirds, where the availability of topographical features such as coastlines may play an important role for the birds' behaviour. We also show that airspeed was significantly influenced by flock size in three species of shorebirds, increasing with increasing flock size. This is contrary to the prediction based on the hypothesis of energy saving by flight in flock formation, but in agreement with empirical findings for migrating terns. The reason why flock size influences airspeed remains unclear, but we propose a mechanistic explanation based on the largest/heaviest individual(s) determining the speed of the flock.

      PubDate: 2017-12-01T12:09:08Z
      DOI: 10.1016/j.anbehav.2017.10.022
      Issue No: Vol. 134 (2017)
       
  • Drivers and consequences of variation in individual social connectivity
    • Authors: Allison E. Williams; Katherine E.L. Worsley-Tonks; Vanessa O. Ezenwa
      Pages: 1 - 9
      Abstract: Publication date: November 2017
      Source:Animal Behaviour, Volume 133
      Author(s): Allison E. Williams, Katherine E.L. Worsley-Tonks, Vanessa O. Ezenwa
      There is a growing interest in identifying specific causes and consequences of variation in individual social behaviour as a means of understanding how different individuals balance the costs and benefits of group living. In this study, we used social networks to examine variation in individual social behaviour in wild Grant's gazelles, Nanger granti, and explored potential drivers and consequences of this variation. First, we quantified two aspects of individual network position (weighted degree and closeness) on a monthly basis for 12 consecutive months and examined life-history (age) and abiotic (rainfall) factors that could explain among-individual variation in network position. Next, we examined the level of within-individual repeatability in network position over time. We then tested for potential consequences of this variation focusing on parasite infection and diet quality. Rainfall and age were strong predictors of variation in closeness but not degree. Interestingly, we found that one aspect of individual network position (closeness) varied over time, while another (degree) was moderately repeatable. The difference in within-individual repeatability of the two measures may be explained by the dependence of closeness on rainfall. In addition, we found that individual network position had consequences for both parasitism and diet, but the magnitude and direction of these effects depended on parasite type, connectivity measure and environmental conditions. Overall, our results suggest that environmental and host factors strongly influence variability in certain aspects of social connectivity in Grant's gazelles, and that abiotic and biotic forces, together, mediate the consequences of social network position.

      PubDate: 2017-09-30T04:54:05Z
      DOI: 10.1016/j.anbehav.2017.08.021
      Issue No: Vol. 133 (2017)
       
  • Familiarity with neighbours affects intrusion risk in territorial red
           squirrels
    • Authors: Erin Siracusa; Stan Boutin; Murray M. Humphries; Jamieson C. Gorrell; David W. Coltman; Ben Dantzer; Jeffrey E. Lane; Andrew G. McAdam
      Pages: 11 - 20
      Abstract: Publication date: November 2017
      Source:Animal Behaviour, Volume 133
      Author(s): Erin Siracusa, Stan Boutin, Murray M. Humphries, Jamieson C. Gorrell, David W. Coltman, Ben Dantzer, Jeffrey E. Lane, Andrew G. McAdam
      Interactions with conspecifics are an important aspect of an individual's environment. Although it is well known that the presence of conspecifics can have important effects on behaviour, in general it is also now acknowledged that the composition of the social environment can vary, and that this variation may have profound effects on individual behaviour and fitness. Using a wild population of North American red squirrels, Tamiasciurus hudsonicus, we investigated the importance of the composition of the social environment in a territorial species by assessing whether the risk of intrusion faced by territory owners varied with the degree of relatedness and familiarity in their social neighbourhoods. To test this, we conducted temporary removals of territory owners and observed the time until intrusion and the identity of intruding individuals. We found that individuals in neighbourhoods with low average familiarity faced a higher risk of intrusion and that unfamiliar neighbours were more likely to intrude. Surprisingly, we found that related neighbours also posed a higher risk of intrusion. The results from our study suggest that familiarity with neighbours may be an ecologically and evolutionarily relevant measure of the social environment, even in a species considered to be ‘asocial’. Future studies should consider the potential importance of the social environment, which has heretofore been mostly overlooked, as a relevant selective pressure in asocial, territorial species.

      PubDate: 2017-09-30T04:54:05Z
      DOI: 10.1016/j.anbehav.2017.08.024
      Issue No: Vol. 133 (2017)
       
  • Interference in early dual-task learning by predatory mites
    • Authors: Inga C. Christiansen; Peter Schausberger
      Pages: 21 - 28
      Abstract: Publication date: November 2017
      Source:Animal Behaviour, Volume 133
      Author(s): Inga C. Christiansen, Peter Schausberger
      Animals are commonly exposed to multiple environmental stimuli, but whether, and under which circumstances, they can attend to multiple stimuli in multitask learning challenges is elusive. Here, we assessed whether simultaneously occurring chemosensory stimuli interfere with each other in a dual-task learning challenge. We exposed predatory mites Neoseiulus californicus early in life to either only conspecifics (kin) or simultaneously conspecifics (kin) and food (thrips or pollen), to determine whether presence of food interferes with social familiarization and, vice versa, whether presence of conspecifics interferes with learning the cues of thrips. We found that N. californicus can become familiar with kin early in life and use kin recognition later in life to avoid kin cannibalism. However, when the juvenile predators were challenged by multiple stimuli associated with two different learning tasks, that is, when they grew up with conspecifics in the presence of food, they were no longer capable of social familiarization. In contrast, the presence of conspecifics did not compromise the predators' ability to learn the cues of thrips. Memory of experience with thrips allowed shorter attack latencies on thrips and increased oviposition by adult N. californicus. Proximately, the stimuli for learning the features of thrips were apparently more salient than those for learning to recognize kin. We argue that, ultimately, learning the cues of thrips at the expense of impeded social familiarization pays off because of negligible cannibalism risk in the presence of abundant food. Our study suggests that stimulus-driven prioritization of learning tasks is in line with the predictions of selective and limited attention theories, and provides a key example of interference in dual-task learning by an arthropod.

      PubDate: 2017-10-08T04:24:56Z
      DOI: 10.1016/j.anbehav.2017.09.005
      Issue No: Vol. 133 (2017)
       
  • Aggression mediates dispersal tendency in an invasive lizard
    • Authors: Marcus Michelangeli; Chelsea R. Smith; Bob B.M. Wong; David G. Chapple
      Pages: 29 - 34
      Abstract: Publication date: November 2017
      Source:Animal Behaviour, Volume 133
      Author(s): Marcus Michelangeli, Chelsea R. Smith, Bob B.M. Wong, David G. Chapple
      Personality-dependent dispersal is a key ecological and evolutionary process that is likely to facilitate the successful movement and colonization/invasion success of species. This dispersal syndrome suggests that dispersers should possess a suite of behavioural tendencies that differ from those of nondispersers, thus influencing the composition of populations in the new range and, ultimately, colonization success. However, dispersal is also often condition dependent, and is probably mediated by the interaction between an individual's personality and environmental and social factors such as competition. Accordingly, we investigated whether dispersal tendency was linked to an activity, exploration and social syndrome and/or aggression in a reptile, the delicate skink, Lampropholis delicata, which has had a successful invasion history via accidental introductions. Contrary to our prediction, we found that dispersal was not related to activity, exploration or social personality traits. Instead, dispersal tendency was associated with aggression: the most aggressive individuals dispersed further and faster than less aggressive individuals. The presence of aggression-dependent dispersal could be due to either (1) dispersers generally being more aggressive than nondispersers or (2) aggressive individuals forcing nonaggressive individuals into hiding, thus impinging on the ability of subordinates to disperse regardless of their personality. Our study highlights the need to consider the ecological context when examining personality-dependent dispersal and suggests that aggression and the social environment can play an important role in dispersal decisions.

      PubDate: 2017-11-20T14:26:17Z
      DOI: 10.1016/j.anbehav.2017.08.027
      Issue No: Vol. 133 (2017)
       
  • Embryonic exposure to a conspecific alarm cue triggers behavioural
           plasticity in juvenile rainbow trout
    • Authors: Amandine Poisson; Claudiane Valotaire; Frédéric Borel; Aline Bertin; Anne-Sophie Darmaillacq; Ludovic Dickel; Violaine Colson
      Pages: 35 - 45
      Abstract: Publication date: November 2017
      Source:Animal Behaviour, Volume 133
      Author(s): Amandine Poisson, Claudiane Valotaire, Frédéric Borel, Aline Bertin, Anne-Sophie Darmaillacq, Ludovic Dickel, Violaine Colson
      In fish, the presence of predator cues in the parental or juvenile environment engenders plasticity in the expression of fear-related behaviours. Whether these cues may engender developmental plasticity when they are present in the environment of embryos remains unexplored. Here, we tested in rainbow trout, Oncorhynchus mykiss: (1) whether exposure to alarm cues during embryonic stages engendered developmental plasticity; and (2) whether an abiotic stressor could also orient the behavioural development of fry. We divided fertilized eggs into three groups: a control nonstressed group (Control), a group of embryos exposed to a conspecific alarm pheromone (e.g. predator-related cue stressor, PS), and a group of embryos that were chronically air exposed for 1min (e.g. abiotic stressor, AS). Stressors were applied once a day, 3 times per week from 19 days postfertilization (dpf) until 52dpf. Between 57 and 143dpf, and for each individual, we assessed the propensity to express fear responses in different contexts and learning performances. When exposed to a novel environment or a novel object, PS fish showed significantly less fear-related behaviour, less freezing and higher activity levels than Control fish. PS fish also showed slower acquisition of a learning task than controls. AS fish did not differ from controls in any test situation. Our results show that in ovo exposure to a natural but not an abiotic signal is a prominent inducer of rainbow trout behavioural plasticity across a number of contexts. Our study provides evidence that the expression of neophobia by fish fry may be modulated by the level of risk perceived by embryos in the environment.

      PubDate: 2017-11-20T14:26:17Z
      DOI: 10.1016/j.anbehav.2017.09.013
      Issue No: Vol. 133 (2017)
       
  • Difference in arrival date at the breeding site between former pair
           members predicts divorce in blue tits
    • Authors: Carol Gilsenan; Mihai Valcu; Bart Kempenaers
      Pages: 57 - 72
      Abstract: Publication date: November 2017
      Source:Animal Behaviour, Volume 133
      Author(s): Carol Gilsenan, Mihai Valcu, Bart Kempenaers
      Divorce occurs when both members of a breeding pair survive to the following year but then pair with other individuals instead of reuniting. Divorce is common in birds, but its frequency can vary widely both between and within species, or even between populations across years. Several explanations for divorce have been described, both adaptive and nonadaptive. Many studies have compared the breeding success of faithful and divorced individuals, but fewer have considered the process of divorce, i.e. the events that lead up to divorce. In this study, we used data from eight breeding seasons to investigate divorce in a population of blue tits, Cyanistes caeruleus, in southern Germany. To compare our results to previous work, we first describe the frequency of divorce and compare the breeding success of divorced and faithful pairs. We then use data from an RFID transponder-based system, where all visits of individuals to any nestbox in the study site are automatically recorded throughout the year, to compare the behaviour of pairs in the interbreeding period. We found that the probability of divorce was not affected by breeding success in Year X. However, divorce was predicted by the difference in arrival time to the study site between the members of Year X pairs. Furthermore, during the interbreeding period, compared to their divorced counterparts, members of faithful pairs had more interactions with one another than with other individuals of the opposite sex. In Year X+1, faithful females started egg laying earlier, had somewhat larger clutches and produced slightly more fledglings, than females that had divorced. We propose that divorce in blue tits is a by-product of separation of the two pair members after the Year X breeding season, leading to asynchrony in the timing of settlement and pair formation in Year X+1.

      PubDate: 2017-11-20T14:26:17Z
      DOI: 10.1016/j.anbehav.2017.09.004
      Issue No: Vol. 133 (2017)
       
  • Chickadees neither win-shift nor win-stay when foraging
    • Authors: Nicole A. Guitar; Caroline G. Strang; Christopher J. Course; David F. Sherry
      Pages: 73 - 82
      Abstract: Publication date: November 2017
      Source:Animal Behaviour, Volume 133
      Author(s): Nicole A. Guitar, Caroline G. Strang, Christopher J. Course, David F. Sherry
      The win-shift versus win-stay distinction supposes that foraging animals use one of two movement rules when searching for food: win-stay to return to locations where they previously found food and win-shift to avoid locations where they previously found food. Win-shift and win-stay rules describe, for example, the behaviour of rats foraging in a radial arm maze, the behaviour of animals in delayed matching and nonmatching to sample tasks, and the behaviour of nectarivorous birds feeding on depleting and replenishing nectar sources. The present study investigated whether black-capped chickadees, Poecile atricapillus, searching for food use win-shift and win-stay rules in response to different reward contingencies. Chickadees first searched multiple spatially dispersed sites for food hidden randomly in these sites, then after several minutes returned to find these sites replenished in the win-stay condition, or empty and other sites baited in the win-shift condition. Birds performed no better than chance at returning to baited sites in the win-stay condition or avoiding previously baited sites in the win-shift condition. Instead, chickadees used preferred search patterns regardless of the win-shift or win-stay contingencies they experienced. Search sequences, however, showed greater stereotypy under win-stay than under win-shift conditions even though the locations of baited sites were determined randomly. Chickadees are year-round residents in relatively small home ranges and may forage using well-established movement rules that, in our experiments, led to neither win-stay nor win-shift behaviour. The stereotypy of search does, however, appear to be influenced by win-stay and win-shift foraging outcomes.

      PubDate: 2017-10-14T14:26:11Z
      DOI: 10.1016/j.anbehav.2017.09.011
      Issue No: Vol. 133 (2017)
       
  • Introductory whistle is sufficient for early song recognition by
           golden-crowned sparrow nestlings
    • Authors: Emily J. Hudson; Daizaburo Shizuka
      Pages: 83 - 88
      Abstract: Publication date: November 2017
      Source:Animal Behaviour, Volume 133
      Author(s): Emily J. Hudson, Daizaburo Shizuka
      Many songbird species have a predisposition to learn conspecific songs, suggesting song learning may be guided by an innate auditory template. Evidence for such a template includes preferential response to conspecific song in early life, even before song learning begins. A prime example of an innate cue for selective song learning is the introductory whistle of white-crowned sparrows, Zon o trichia leucophrys. The songs of its sister species, the golden-crowned sparrow, Zon o trichia atricapilla, also contain an introductory whistle, which differs in structure from that of white-crowned sparrows. Here we tested the ability of nestling golden-crowned sparrows in a sympatric population to discriminate between conspecific and heterospecific songs based on introductory whistles alone, prior to the onset of song learning. Golden-crowned sparrow nestlings responded with more chirps to playbacks of conspecific whistles than to heterospecific (white-crowned sparrow) whistles, and they responded similarly to full conspecific songs and conspecific whistles alone. We suggest that the introductory whistle alone is sufficient for song recognition in the golden-crowned sparrow. We discuss similarities and differences in the role of the introductory whistle between these sister taxa, and how this divergent song phrase may share a role in species recognition in both sister species. Identifying the cues underlying song recognition prior to song learning could be key to understanding the evolution of behavioural isolation between closely related songbird species.

      PubDate: 2017-10-14T14:26:11Z
      DOI: 10.1016/j.anbehav.2017.09.018
      Issue No: Vol. 133 (2017)
       
  • Sir Patrick (Pat) P.G. Bateson FRS (1938–2017)
    • Authors: Carel ten Cate
      Pages: 89 - 90
      Abstract: Publication date: November 2017
      Source:Animal Behaviour, Volume 133
      Author(s): Carel ten Cate


      PubDate: 2017-10-14T14:26:11Z
      DOI: 10.1016/j.anbehav.2017.09.010
      Issue No: Vol. 133 (2017)
       
  • The give and take of food sharing in Sumatran orang-utans, Pongo abelii,
           and chimpanzees, Pan troglodytes
    • Authors: Katja Liebal; Federico Rossano
      Pages: 91 - 100
      Abstract: Publication date: November 2017
      Source:Animal Behaviour, Volume 133
      Author(s): Katja Liebal, Federico Rossano
      Proximate factors of primate food sharing, in contrast to its evolutionary explanations, have received little attention. Active food sharing is considered prosocial, since possessors may benefit others by spontaneously passing food or by reacting to ‘signals of need’. However, in contrast to passive sharing, active food sharing is rare in most nonhuman primates. Surprisingly, previous research showed that captive Sumatran orang-utans actively share food more frequently than chimpanzees and bonobos, and hence, appear more prosocial. Yet these comparisons with the two Pan species were relying on previously published studies, which differed with regard to methods and food types used. Here we used the identical procedure and food type to compare the food-sharing behaviour of 10 captive Sumatran orang-utans and 18 chimpanzees, in situations where individuals could monopolize a sharable food source. We focused on communicative behaviours used to initiate food transfers, and assessed whether and how much food was transferred in response to these initiation attempts. In both species, most transfers were initiated by taking the food, resulting in passive sharing, while active sharing by offering food or after requesting it occurred only rarely. However, orang-utans differed from chimpanzees in several aspects. Because the food was mostly monopolized by the adult male, orang-utans attempted to initiate food transfers more frequently, resisted more to taking attempts, and were less likely to transfer whole food items. In both species, requests were less likely to result in food transfers, indicating that in situations involving access to food, they do not necessarily respond to ‘signals of need’. We argue that in addition to instances of active sharing, other factors such as the degree of food monopolization, response rates to ‘signals of need’, and the quality and quantity of transferred food need to be considered to gain a more detailed picture of prosociality across species.

      PubDate: 2017-10-14T14:26:11Z
      DOI: 10.1016/j.anbehav.2017.09.006
      Issue No: Vol. 133 (2017)
       
  • Choosy males in Jamaican field crickets
    • Authors: Susan M. Bertram; Michelle J. Loranger; Ian R. Thomson; Sarah J. Harrison; Genevieve L. Ferguson; Mykell L. Reifer; Deborah H. Corlett; Patricia Adair Gowaty
      Pages: 101 - 108
      Abstract: Publication date: November 2017
      Source:Animal Behaviour, Volume 133
      Author(s): Susan M. Bertram, Michelle J. Loranger, Ian R. Thomson, Sarah J. Harrison, Genevieve L. Ferguson, Mykell L. Reifer, Deborah H. Corlett, Patricia Adair Gowaty
      Male mate choice is an often neglected aspect of sexual selection studies. While theory predicts that females should exhibit mate choice due to their comparatively greater investment in gametes, males may also exhibit mate choice for a variety of reasons, including seeking mates with greater fecundity. Furthermore, males may exhibit discriminant or indiscriminate mate choice as a function of their own intrinsic characteristics, such as body size or condition. Here we experimentally evaluated male Jamaican field cricket, Gryllus assimilis, mating preferences using randomly selected females and determined how both male and female morphology (body size and residual mass) and male signalling behaviour influence male mate preference. Results show that male crickets exhibit mating preferences, with larger males tending to exhibit more consistent mate preferences than smaller males. Contrary to predictions, males did not prefer larger or relatively heavier females, suggesting that males may not be basing their choosiness on these proxy measures of female fecundity. Our findings highlight the need for continued research on male mate choice and identifying the intrinsic characteristics of both sexes that drive them.

      PubDate: 2017-10-14T14:26:11Z
      DOI: 10.1016/j.anbehav.2017.09.016
      Issue No: Vol. 133 (2017)
       
  • Lower settlement following a forced displacement experiment: nonbreeding
           as a dispersal cost in a wild bird'
    • Authors: Marion Germain; Tomas Pärt; Blandine Doligez
      Pages: 109 - 121
      Abstract: Publication date: November 2017
      Source:Animal Behaviour, Volume 133
      Author(s): Marion Germain, Tomas Pärt, Blandine Doligez
      Dispersal is a key life history trait impacting ecological and evolutionary processes. Yet, the fitness consequences of dispersal remain poorly investigated. Using a displacement experiment of 616 individuals in a patchy population of collared flycatchers, Ficedula albicollis, we investigated behavioural responses to forced movement in terms of settlement, subsequent breeding performance and return rate. Newly arrived birds were caught and displaced between patches or released back in the patch of capture. We analysed (1) the probability of successful settlement within the study area, (2) for displaced birds, the probability of accepting the forced movement rather than returning to the patch of capture, (3) components of reproductive performance and (4) return rate in subsequent years according to experimental treatment. The probability of settling within the study area tended to be lower for displaced than control birds and was lower for immigrants than local birds. This suggests that displacement induced long-distance dispersal movements or nonbreeding, which could reflect costs of unfamiliarity with the environment. Nondispersers (individuals caught early in the breeding season in the same patch as their previous one) were more likely to return to their patch of capture, probably because of higher benefits of familiarity. Once individuals had settled, their breeding performance did not vary markedly between treatments, although displaced individuals that did not return to their patch of capture raised lighter young than other individuals. This could indicate a lower phenotypic quality of these individuals or, again, a cost of breeding in an unfamiliar environment. Finally, individuals that settled (and nondispersers) were more likely to return to the study area in subsequent years than individuals that disappeared (and immigrants/dispersers, respectively). Together, these results suggest that, in addition to the costs of transience, dispersal (here forced) may entail costs linked to settlement in an unfamiliar habitat.

      PubDate: 2017-10-14T14:26:11Z
      DOI: 10.1016/j.anbehav.2017.09.001
      Issue No: Vol. 133 (2017)
       
  • Uncovering the origins of dog–human eye contact: dingoes establish eye
           contact more than wolves, but less than dogs
    • Authors: Angie M. Johnston; Courtney Turrin; Lyn Watson; Alyssa M. Arre; Laurie R. Santos
      Pages: 123 - 129
      Abstract: Publication date: November 2017
      Source:Animal Behaviour, Volume 133
      Author(s): Angie M. Johnston, Courtney Turrin, Lyn Watson, Alyssa M. Arre, Laurie R. Santos
      Through domestication, dogs have developed a robust ability to form interspecific bonds with humans. Recent work comparing dogs and wolves suggests that eye contact is an important behaviour underlying these social bonds; however, it remains unclear how this feature of interspecific social bonding evolved. We explored eye contact in a unique comparison species that represents an intermediate point in canid domestication: the Australian dingo (Canis dingo). Across two different studies with two different human handlers, we examined dingo-initiated eye contact using a method similar to one previously used with dogs and wolves. In contrast to wolves tested previously, dingoes initiated eye contact with a human, but did so for a shorter time than dogs. Given that dingoes share only an early domestication history with dogs, our results suggest that the motivation to initiate eye contact with humans may have evolved relatively early in domestication. However, the tendency to maintain prolonged eye contact with a familiar human may have evolved later. These results shed new light on the evolutionary steps by which humans and dogs developed their unique social bond.

      PubDate: 2017-10-14T14:26:11Z
      DOI: 10.1016/j.anbehav.2017.09.002
      Issue No: Vol. 133 (2017)
       
  • Consistent individual variation across interaction networks indicates
           social personalities in lemurs
    • Authors: Ipek G. Kulahci; Asif A. Ghazanfar; Daniel I. Rubenstein
      Abstract: Publication date: Available online 9 December 2017
      Source:Animal Behaviour
      Author(s): Ipek G. Kulahci, Asif A. Ghazanfar, Daniel I. Rubenstein
      Group members interact with each other during multiple social behaviours that range from aggressive to affiliative interactions. It is not known, however, whether an individual's suite of social behaviours consistently covaries through time and across different types of social interactions. Consistent social behaviour would be advantageous in groups, especially when individuals need to remember their group members' social roles and preferences in order to keep track of social relationships and predict conspecifics' future behaviour. Here, we address whether social behaviour of ringtailed lemurs, Lemur catta, is consistent through time and across four interaction networks (aggression, grooming, contact calling, scent marking). We quantified variation in social behaviour through four network centrality measures including outdegree, outstrength, betweenness and eigenvector centrality. Comparing lemurs' measures across 2 years revealed that network centrality remained consistent between years. Lemurs' centrality also stayed consistent across interaction networks: individuals with high centrality in one interaction network also had high centrality in the other networks, even when we controlled for sex-based variation in social behaviour. Thus, regardless of their sex, some individuals were highly social and frequently groomed others, initiated aggressive interactions and responded to others' contact calls and scent marks. Lemurs also had preferred social partners they frequently interacted with across years and across multiple behaviours. In particular, lemurs frequently responded to the contact calls and the scent marks of the conspecifics they had frequently groomed. Together, these results demonstrate that individual variation in lemur social behaviour is not context specific, but instead persists through time and across multiple social interactions. Such consistent behaviour provides evidence of social personalities, which may influence individuals' interaction styles, including how socially active they are and with whom they interact.

      PubDate: 2017-12-12T02:10:15Z
      DOI: 10.1016/j.anbehav.2017.11.012
       
  • Where should we meet' Mapping social network interactions of sleepy
           lizards shows sex-dependent social network structure
    • Authors: Orr Spiegel; Andrew Sih; Stephan T. Leu; C. Michael Bull
      Abstract: Publication date: Available online 6 December 2017
      Source:Animal Behaviour
      Author(s): Orr Spiegel, Andrew Sih, Stephan T. Leu, C. Michael Bull
      Social network analyses allow researchers to describe patterns of social interactions and their consequences in animal societies. Since direct observations in natural settings are often difficult, researchers often use tracking technologies to build proximity-based social networks. However, because both social behaviour (e.g. conspecific attraction) and environmental heterogeneity (e.g. resources attracting individuals independently) affect rates of interaction, identifying the processes that shape social networks is challenging. We tracked sleepy lizards, Tiliqua rugosa, using global positioning system (GPS) telemetry to investigate whether they show conspecific attraction or avoidance beyond any shared space use driven by environmental heterogeneity. Since these lizards have strong pair bonds and nonoverlapping core home ranges, we predicted different interaction rates between inter- and intrasex dyads and compared social network indices among dyad types (male–male, female–female and intersex) using node-identity permutation tests. We also mapped interactions onto the home ranges (using distance from the centre as an index) and contrasted observed social networks with those expected from a spatially explicit null model. We found that dyad types differed in their interaction patterns. Intersex dyads had stronger connections (higher edge weight) than a null expectation, and stronger than for same-sex dyads. Same-sex dyads did not differ in edge weight from the null expectation, but were significantly more common (higher degree). Males had larger home ranges than females and consequently male–male dyads interacted further away from their home range centres. Moreover, the locations of these interactions also differed from the null expectations more strongly than other dyad types. Hence, we conclude that males predominantly interacted with each other at the peripheries of their home range, presumably reflecting territorial behaviour. By applying a novel analysis technique, we accounted for the nonsocial component of space use and revealed sex-specific interaction patterns and the contribution of conspecific attraction to the social structure in this species. More generally we report how mapping the locations of nonrandom interaction rates provides broad information on the behaviours they represent.

      PubDate: 2017-12-12T02:10:15Z
      DOI: 10.1016/j.anbehav.2017.11.001
       
  • Guidelines for the treatment of animals in behavioural research and
           teaching
    • Abstract: Publication date: Available online 6 December 2017
      Source:Animal Behaviour


      PubDate: 2017-12-12T02:10:15Z
       
  • Function of vocalization length and warble repertoire size in
           orange-fronted conures
    • Authors: Thorsten J.S. Balsby; Erin R.B. Eldermire; Jessica K. Schnell; Angelika Poesel; Rachel E. Walsh; Jack W. Bradbury
      Abstract: Publication date: Available online 24 November 2017
      Source:Animal Behaviour
      Author(s): Thorsten J.S. Balsby, Erin R.B. Eldermire, Jessica K. Schnell, Angelika Poesel, Rachel E. Walsh, Jack W. Bradbury
      Bird vocalizations consist of songs and calls. The calls tend either to be given singly or to consist of multiple elements given in a rapid string. The multi-element bird calls of some nonpasserines resemble passerine song and can contain many diverse elements. Multi-element vocalizations can change the signal message by varying the number of elements and/or the diversity and selection of element types. The use of multi-element variation has been extensively studied in passerine songs, but only rarely in nonpasserines. Here we examined two multi-element vocalization types in a wild parrot, the orange-fronted conure, Eupsittula canicularis: ‘warbles’ consist of diverse elements (heterotypic) whereas ‘peaches’ consist of repetitions of the same element (homotypic). Both call types are used in aggressive interactions between pairs or flocks. We used playbacks to wild conure flocks in Costa Rica to determine whether the number of elements (both types) and/or the diversity of elements (warble repertoire size) produced differentiable responses. Both short and long peach call series usually elicited retreat, but longer series led to reduced warbling and increased soft contact calls (zip calls) when responses were compared with those of short series. The warble stimuli mainly affected the approach behaviour leaving most call rates unaffected: more flocks left the area in response to long warbles with large repertoires, whereas short, small repertoire stimuli resulted in a closer approach. Both experiments showed that the length of both types of multi-element call and element diversity in warbles are salient to the wild conures. The results suggest that longer series of both call types and higher diversity warbles may be perceived by the birds as more aggressive, leading to the observed patterns of approach, retreat and interaction. The results suggest that vocal complexity in parrots has a signal value similar to that found in passerines.

      PubDate: 2017-12-01T12:09:08Z
      DOI: 10.1016/j.anbehav.2017.10.025
       
  • Discovering structural complexity and its causes: Breeding aggregations in
           horseshoe crabs
    • Authors: H. Jane Brockmann; Colette M. St Mary; José Miguel Ponciano
      Abstract: Publication date: Available online 23 November 2017
      Source:Animal Behaviour
      Author(s): H. Jane Brockmann, Colette M. St Mary, José Miguel Ponciano
      In some species, especially those that form breeding aggregations, males form groups around females vying for fertilizations. These mating groups are often highly variable in size even during a single breeding event. We examined this variation in the American horseshoe crab, Limulus polyphemus, a species in which some females (nesting in pairs) attract additional males (satellites) and spawn in groups whereas others spawn only with their attached male. The observed distribution of group sizes often consists of an overabundance of pairs with no satellite males and groups with large numbers of satellites. We characterized this variation using well-known models of count data, such as the Poisson and negative binomial distributions, and evaluated how operational sex ratio (OSR) and pair density contribute to the observed variation. We complemented this descriptive approach with spatially explicit simulations of the group formation process. By comparing our simulation results to the observed breeding aggregation data, we identified how simple behavioural rules might contribute to the variation we observe. Those rules amount to hypotheses about pair and satellite arrival at the beach and satellite sampling of and choice among pairs. We found that the observed variation could be explained by a consistent high frequency of females that attract satellites in combination with males that sample different fractions of the beach as pair density and OSR vary. Furthermore, our simulations suggested that males are not choosy in joining pairs on the beach, despite variation among pairs in the fertilization success satellites can achieve. This suggests that new insights might come from investigating the costs and benefits of male choice and the sensory mechanisms satellite males use to assess the breeding aggregation before coming ashore.

      PubDate: 2017-12-01T12:09:08Z
      DOI: 10.1016/j.anbehav.2017.10.020
       
  • Editors Page
    • Abstract: Publication date: November 2017
      Source:Animal Behaviour, Volume 133


      PubDate: 2017-11-20T14:26:17Z
       
  • Association Page
    • Abstract: Publication date: November 2017
      Source:Animal Behaviour, Volume 133


      PubDate: 2017-11-20T14:26:17Z
       
  • Behave: The biology of humans at our best and worst, Robert M. Sapolsky.
           Penguin Press (2017), 790
    • Authors: Gregory Ball
      Abstract: Publication date: December 2017
      Source:Animal Behaviour, Volume 134
      Author(s): Gregory F. Ball


      PubDate: 2017-11-11T14:35:15Z
       
  • Big groups attract bad eggs: brood parasitism correlates with but does not
           cause cooperative breeding
    • Authors: Michael Wells; Keith Barker
      Abstract: Publication date: November 2017
      Source:Animal Behaviour, Volume 133
      Author(s): Michael T. Wells, F. Keith Barker
      There has been great interest in how complex social behaviours such as cooperative breeding evolve and are maintained; however, it is still unclear what exact phenomena trigger the transition to cooperative breeding. Recent work in birds has suggested a number of factors associated with cooperative breeding, including environmental uncertainty and brood parasitism. One recent study found a correlation between brood parasitism and cooperative breeding, but it examined this relationship from a geographically restricted perspective. We investigated evolutionary correlations between brood parasitism and cooperative breeding at a global scale, including nearly half of all bird species and brood parasites. At a global level, we found a strong positive correlation between cooperative breeding and brood parasitism. However, when partitioned regionally, we found that the global pattern was driven exclusively by relationships within Africa and Australia, suggesting that any causal relationship in the transition to cooperative breeding is idiosyncratic. In addition, we found that even where a correlation was supported, transition rates between states were more consistent with cooperative breeding attracting brood parasitism, rather than brood parasites driving the evolution of cooperative breeding, weakening any hypothesized causal connection.

      PubDate: 2017-10-08T04:24:56Z
       
 
 
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